arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2103.01484cs.LGeess.SPmath.OC
收藏

基于Frank-Wolfe方法的在线正交字典学习

Online Orthogonal Dictionary Learning Based on Frank-Wolfe Method

Hong Kong University of Science and Technology(香港科技大学)

Ye Xue, Vincent Lau

摘要:

字典学习是信号处理和机器学习中广泛使用的一种无监督学习方法。现有的大多数词典学习工作都是以离线方式进行的。词典学习主要有两种离线方式。一种是对字典和稀疏代码进行替代优化;另一种方法是通过将字典限制在正交组上来优化字典。后者被称为正交字典学习,其具有较低的复杂度实现,因此,它更有利于低成本设备。然而,现有的正交字典学习方案只能处理批量数据,不能在线实现,不适用于实时应用。本文提出了一种新的在线正交字典计划,动态学习的字典从流数据,而无需存储的历史数据。该方案包括一个新的问题制定和有效的在线算法设计与收敛性分析。在问题的制定,我们放松正交约束,使一个有效的在线算法。在算法设计中,我们提出了一种新的基于Frank-Wolfe的在线算法,其收敛速度为O(lnt/t^(1/4))。的收敛速度的关键系统参数也来自。合成数据和真实世界的传感器读数的实验证明了所提出的在线正交字典学习方案的有效性和效率。

英文摘要:

Dictionary learning is a widely used unsupervised learning method in signal processing and machine learning. Most existing works of dictionary learning are in an offline manner. There are mainly two offline ways for dictionary learning. One is to do an alternative optimization of both the dictionary and the sparse code; the other way is to optimize the dictionary by restricting it over the orthogonal group. The latter one is called orthogonal dictionary learning which has a lower complexity implementation, hence, it is more favorable for lowcost devices. However, existing schemes on orthogonal dictionary learning only work with batch data and can not be implemented online, which is not applicable for real-time applications. This paper proposes a novel online orthogonal dictionary scheme to dynamically learn the dictionary from streaming data without storing the historical data. The proposed scheme includes a novel problem formulation and an efficient online algorithm design with convergence analysis. In the problem formulation, we relax the orthogonal constraint to enable an efficient online algorithm. In the algorithm design, we propose a new Frank-Wolfe-based online algorithm with a convergence rate of O(ln t/t^(1/4)). The convergence rate in terms of key system parameters is also derived. Experiments with synthetic data and real-world sensor readings demonstrate the effectiveness and efficiency of the proposed online orthogonal dictionary learning scheme.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑